A cylinder body used in an automobile engine is generally composed of a cylinder liner and an outside aluminum sheath of the cylinder liner, and it produces power by a piston sliding up and down, which is driven by the exploding of the fuel in the combustor in the cylinder liner. Therefore, the inside surface of the cylinder liner need wear resistance of some, and the outside surface of the cylinder liner need powerful bite force, so as to fit together with the outside aluminum sheath firmly, to avoid the aluminum sheath break away.
Enough contact bite force must be provided between the material of the cylinder body and the surface of the cylinder liner, in order to have a good thermal conductivity, so as to have a good engine cooling performance, and reduce the deformation of holes in the cylinder liner at same time. Therefore, it is expected to have a cylinder liner with improved bite force and joint strength. However, there are following defects in the existing cylinder liner:
(1) Bosses and pits are random distributed on the outside surface of the cylinder liner, wherein the bosses is irregular-shaped, such as taper, convex or round and so on. In the manufacture of this cylinder liner, due to the irregular-shape of the bosses, the molten material used for manufacturing the cylinder liner is difficult to fill to each boss desirably, so it is difficult to form ideal protrusions that decrease the bite force between the cylinder liner material and the outside aluminum sheath.
(2) There is another cylinder liner with an aluminum silicon powder layer thermal sprayed on the outside surface of the cylinder body. The thermal spraying layer can effectively reduce the defect of pore between the cylinder liner and the cylinder body, to improve the joint strength between the cylinder liner and the cylinder body, but the process is difficult to control and the cost is high.